/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 86183
 * Date: 2022-09-17
 * Time: 8:35
 */
public class MySingleList {
    static class ListNode {
        public int val;
        public ListNode next;

        public ListNode(int val) {
            this.val = val;
        }
    }
        public ListNode head;//默认初始化，为null

        public void display() {
            ListNode cur = this.head;
            while (cur != null) {
                System.out.print(cur.val + " ");
                cur = cur.next;
            }
            System.out.println();
        }

        //头插法
        public void addFirst(int data){
            ListNode cur = new ListNode(data);
            cur.next = head;
            head = cur;
        }

        //尾插法
        public void addLast(int data){
            ListNode node = new ListNode(data);
            ListNode cur = head;
            if(cur == null){
                this.head = node;
            }else {
                while (cur.next != null) {
                    cur = cur.next;
                }
                cur.next = node;
            }
        }

        //任意位置插入,第一个数据节点为0号下标
        public void addIndex(int index, int data) throws indexWrongful {
            if(index < 0||index > size()){
                throw new indexWrongful("index位置不合法");
            }
            if(index == 0){
                addFirst(data);
                return;
            }
            if(index == size()){
                addLast(data);
                return;
            }
            ListNode node = new ListNode(data);
            ListNode cur = finndIndexSubone(index);
            node.next = cur.next;
            cur.next = node;
        }
        private ListNode finndIndexSubone(int index){
            ListNode cur = this.head;
            while (index -1 != 0){
                cur = cur.next;
                index--;
            }
            return  cur;
        }

        //查找是否包含关键字key是否在单链表当中
        public boolean contains(int key){
            ListNode cur = this.head;
            while(cur != null){
                if(cur.val == key){
                    return true;
                }
                cur =cur.next;
            }
           return false;
        };

        //删除第一次出现关键字为key的节点
        public void remove(int key){
            if(this.head == null){
                return;
            }
            if(this.head.val == key){
                this.head = this.head.next;
                return;
            }
            ListNode cur = findPrevOfkey(key);
            if(cur == null){
                System.out.println("没有该数据");
                return;
            }
            ListNode q = cur.next;
            cur.next = q.next;

        }
        private ListNode findPrevOfkey(int key){
            ListNode cur = this.head;
            while (cur.next !=null){
                if(cur.next.val == key){
                    return cur;
                }
                cur = cur.next;
            }
            return null;
    }

        //删除所有值为key的节点
        public void removeAllKey(int key){
            if(this.head == null){
                return;
            }
            ListNode prev = this.head;
            ListNode cur = this.head.next;
            while (cur != null){
                if(cur.val == key){
                    prev.next = cur.next;
                    cur = cur.next;
                }else {
                    prev  = cur;
                    cur = cur.next;
                }
            }
            if(this.head.val == key){
                this.head = this.head.next;
            }
        }

        //得到单链表的长度
        public int size(){
            int count = 0;
            ListNode cur = this.head;
            while (cur != null){
                count++;
                cur = cur.next;
            }
            return count;
        }

        public void clear(){
             this.head = null;
        }


}